Deaeration system and method for flexible packages

ABSTRACT

System for allowing removal of air from the interior of flexible packages, in which material can be found, including a conveyor transporting and supporting the bottom of the flexible packages or package, a second sub-system holding the top part of the package and an air extraction system. The package is raised vertically while being displaced along the conveyor. Removing the air from the packages before closing them results in a flat and straight flap, while reducing the distance between the product and the sealed or sewn joint. The process is accomplished through a continuous displacement of the package. These advantages result in packing material savings. A method for allowing removal of air is also disclosed.

RELATED APPLICATIONS

This application is the U.S. National Phase under 35 U.S.C. §371 ofInternational Application No. PCT/CA2009/000785, filed on Jun. 4, 2009,which in turn claims the benefit of U.S. Provisional Application No.61/058,805, filed on Jun. 4, 2008, the disclosures of which Applicationsare incorporated by reference herein.

FIELD OF THE INVENTION

The present invention generally relates to packaging systems. Moreparticularly, the present invention relates to a deaeration system forflexible packages and a method associated thereto.

BACKGROUND OF THE INVENTION

Several different types of products are packaged typically in flexiblepackages. After filling of the packages, in order to reduce the overallvolume of the package; it is often desired to remove air remainingwithin the package before sealing thereof. Removing the air from thepackages before closing them results in a flat and straight flap (upperpart of the package above the product). Then, it is possible for theclosing system belts to be closer to the product. Therefore, it ispossible to reduce the distance between the product and the sealed orsewn joint. By reducing this distance, the freeboard (distance betweenthe upper part of the package and the product level when the package isfull) is also reduced. The required length of empty bags is consequentlyreduced, which result in packing material savings (economic andecological savings).

The invention described in U.S. Pat. No. 7,316,102 involves an apparatusfor extracting air from within flexible packages. The package isdisplaced along a conveyor system and has air removed therefrom under ahood which is linked to a subsequent closing mechanism.

However, flexible packaging customers still have several requirementsthat are not completely satisfied with existing deaeration systems,including:

-   -   Reducing a warehouse bursting packages problem;    -   Reducing the amount of air in packages;    -   Maintaining current productivity, reliability and quality;    -   Using the smallest footprint possible (ex.: providing 7 feet        maximum length available for the footprint);    -   Providing flexible package sizes (from 13″ to 20″); and    -   Using less freeboard.

Consequently, there is still presently a need for a deaeration systemand associated method which offers superior results in terms of theefficiency of the removal of air from the flexible package and addressesthe above requirements.

SUMMARY OF THE INVENTION

The present invention addresses at least one of the above-mentionedneeds.

More particularly, the present invention provides a system for removalof air from an interior of a flexible package before closure thereof,the system comprising:

-   -   a lower conveyor sub-system for continuously displacing the        package along a length of the system;    -   an upper driving sub-system holding continuously an upper part        of the package, keeping the upper part closed along a length of        its displacement, said upper driving sub-system comprising at        least one perforated belt bag-opening sub-system comprising:        -   at least one pair of adjacent guiding structures, each            guiding structure having a profile surface facing a            corresponding profile surface of the opposite guiding            structure;        -   a plurality of driving belts, each belt circulating around a            corresponding guiding structure of the at least one pair of            guiding structures, each of said belts following a path            along the corresponding profile of the guiding structure on            which the driving belt is travelling;        -   a pulley system for driving displacement of the plurality of            driving belts around the guiding structures; and        -   a belt sub-system vacuum source applying vacuum behind the            belts, said at least one bag-opening sub-system spreading            partially open the upper part of the package at a specific            location along the length of the system when passing between            the profile surfaces of adjacent guiding structures, said            upper driving sub-system being synchronized with the lower            conveyor sub-system;    -   and        -   a deaeration port located above the bag-opening sub-system            allowing removal of air from the interior of the package            when the package is positioned under the port.

Preferably, the lower conveyor sub-system has a profile or shape thatallows the package to increase in height sufficiently to remove verticaltension from the top of the package.

Preferably, the bag-opening sub-system has a shape that allows the upperpart of the package to be partially opened by a vacuum source connectedto bag-opening sub-system.

Preferably, the air removal section displaces the package through aperforated belt system or any other equivalent system allowingrepositioning of the package and allowing passage of a certain quantityof air.

Preferably, the air removal section opens a portion (in the upper part)of the package. In this section, the upper sides of the package aremaintained against the driving belts to spread it out, partially openingthe package. In fact, a source of vacuum applied behind the perforatedbelts, a pulley desynchronisation and a curved block or guidingstructure constrain the two belts to follow a curved path (opposite ofone another).

The present invention also provides a method for removing air from theinterior of flexible packages before closure thereof, comprising thefollowing steps:

-   -   a) providing a system for removal of air comprising:        -   a lower conveyor sub-system for continuously displacing the            package along a length of the system;        -   an upper driving sub-system holding continuously an upper            part of the package, keeping the upper part closed along a            length of its displacement, said upper driving sub-system            comprising at least one perforated belt bag-opening            sub-system comprising:            -   at least one pair of adjacent guiding structures, each                guiding structure having a profile surface facing a                corresponding profile surface of the opposite guiding                structure;            -   a plurality of driving belts, each belt circulating                around a corresponding guiding structure of the at least                one pair of guiding structures, each of said belts                following a path along the corresponding profile of the                guiding structure on which the driving belt is                travelling;            -   a pulley system for driving displacement of the                plurality of driving belts around the guiding                structures;            -   a belt sub-system vacuum source applying vacuum behind                the belts, said at least one bag-opening sub-system                spreading partially open the upper part of the package                at a specific location along the length of the system                when passing between the profile surfaces of adjacent                guiding structures, said upper driving sub-system being                synchronized with the lower conveyor sub-system;    -   and        -   a deaeration port located above the bag-opening sub-system            allowing removal of air from the interior of the package            when the package is positioned under the port,    -   b) displacing continuously the package along a horizontal        direction, using the low conveyor sub-system;    -   c) maintaining continuously an upper part of the package closed        along a length of its displacement, using the upper driving        sub-system;    -   d) partially opening the upper part of the package at a specific        location along the length of the system, using said bag-opening        sub-system; and    -   e) removing air from the interior of the package when the        package is positioned, at said specific location, using the        deaeration port.

According to the present invention, there is also provided a system forremoving air from an interior of a flexible package before closurethereof, comprising:

-   -   displacement means for continuously displacing the package along        a horizontal direction while supporting a bottom of the package        and holding an upper part of the package at all times;    -   raising means for raising the bottom of the package along a        distance of travel of the package to reduce vertical tension        within the package; and    -   opening means for opening a portion of the upper part of the        package, said opening means comprising:        -   at least one pair of guiding structures, each guiding            structure having a profile surface facing a corresponding            profile surface of the opposite guiding structure;        -   a plurality of driving belts, each belt circulating around a            corresponding guiding structure of the at least one pair of            guiding structures, each of said belts following a path            along the corresponding profile of the guiding structure on            which the driving belt is travelling;        -   a pulley system for driving displacement of the plurality of            driving belts around the guiding structures; and        -   a belt sub-system vacuum source applying vacuum behind the            belts, said bag-opening sub-system spreading partially open            the upper part of the package at a specific location along            the length of the system when passing between the profile            surfaces of adjacent guiding structures, while maintaining            displacement of the package;    -   and        -   a deaeration port located above the opening means allowing            removal of air from the interior of the package when the            package is positioned under the port.

The system according to the present invention offers the followingadvantages:

-   -   Capability of staying in control of the top of package    -   Keeping current packaging machine configuration    -   Capability of being added at the exit of machine    -   Capability to remove air “in-line” (continuously) with up to 150        fpm linear speed    -   Keeping high level of reliability    -   Preventing air entrance into the package (after air extraction        and prior to sealing)    -   Package shape conditioning after sealing

A non-restrictive description of preferred embodiments of the inventionwill now be given with reference to the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the system according to a preferred embodimentof the present invention;

FIG. 2 is another side view of the system shown in FIG. 1 with thepackages removed and the upper housing installed;

FIG. 3 is another side view of the system shown in FIG. 2 with the upperhousing removed;

FIG. 4 is a another side view of the system according to a preferredembodiment of the present invention;

FIG. 5 is a side close-up view of the upper driving system shown in FIG.4;

FIGS. 6A and 6B are top and side-cut views respectively of an aluminiumblock or guiding structure and associated hardware from FIG. 4;

FIG. 7 is a detailed side view of the upper driving system (air removalsection) shown in FIG. 5;

FIG. 8 is another side close-up view of the upper driving system shownin FIG. 4;

FIG. 9 is a side view of the system shown in FIG. 4, during itsoperation with packages, illustrating different work stations;

FIG. 10 is a top view of part of the upper driving system shown in FIG.4;

FIGS. 11 a and 11 b are front views of the interaction of a package witha system according to another preferred embodiment of the presentinvention, showing lower and upper positions of the package;

FIGS. 12 a to 12 c are side views of the interaction of a package with asystem according to another preferred embodiment of the presentinvention, as the package travels along the conveyor system;

FIGS. 13 a and 13 b are perspective views of the interaction of apackage with the system shown in FIG. 11, before and after removal ofair;

FIGS. 14 a to 14 d are perspective views of the interaction of a packagewith the system shown in FIG. 11, illustrating air extraction, vacuumshutdown and maintaining of the condition of the package afterextraction.

FIGS. 15A to 15C are side, top and front views respectively of thesystem shown in FIG. 1 with the upper housing and associated supportstructure installed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

As shown in FIGS. 1 to 3 and 15A to 15C, a deaeration system 10 forflexible packages 12 according to the present invention is shown. Thesystem comprises a lower conveyor sub-system 14. The system 10 also hasan upper driving system 16 maintaining continuously the upper part ofthe package 12 closed along a significant length of its displacement.The upper driving system 16 comprises one or several bag-openingsub-systems, preferably connected to a vacuum source 18, that allowsopening of the flexible package at a specific location when the packagetravels along the upper driving system 16 and on the lower conveyorsystem 14. The system also comprises a deaeration port 20 located abovethe upper driving system 16 connected to the vacuum source 18 thatallows removal of air from the interior of the package 12 when thepackage is positioned under the deaeration port 20 by the upper drivingsystem 16 and the lower conveyor system 14, under the bag-openingsub-system.

In the present application, it is to be understood that the deaerationport can be an aspiration port, a dedusting port, a vacuum port, asystem connected to a vacuum source or any other equivalent system knownto the person of skill in the art which is capable of removing air orsubstances from the package.

As better shown in FIG. 4, the lower conveyor 14 includes a steel frame30, conveyor rollers 32 and a conveyor belt 34. The conveyor belt isdriven by a motor 36 at a constant linear velocity in order to displacethe package towards the closing or sealing systems located downstream.The steel frame has a shape 38 that allows the conveyor belt and thepackage to rise along a certain height while translating along thesystem.

As better shown in FIG. 5, the system 40 controlling the upper part ofthe package has three sections, 42,44,46. The first 42 and third 46sections are made of aluminum blocks or guiding structures, pulleys andbelts. The upper part of the package is maintained closed throughpressure exerted by the belts on the package. The belts are driven by amotor 48 at the same linear velocity as the lower conveyor belt.

As better shown in FIGS. 6A and 6B and 7, the mid-section of the system44 includes aluminum blocks or guiding structures 50 having a specialshape, perforated belts 52, pulleys 54 and various other pieces ofhardware. On each side of the system, a tube 56 connected to a highdebit ventilator removes the air through an opening in the aluminumblocks or guiding structures and through the perforated belt.

As better shown in FIG. 8, the vacuum removal system 18 is a deaerationport 60 located above the upper section. This port is connected to ahigh flow ventilator 62 for removal of the air.

Explanation of the Operation of the System

The package arrives from the packaging system with a certain quantity ofair inside thereof, in addition to the packaged product. The productreaches a certain height within the package. The upper part of thepackage which is not filled is designated as the freeboard. Duringremoval of air from the package, the sides of the freeboard approach oneto another. Raising the package using the shape of the bottom conveyorwill result in loose freeboard. Once an amount of play (loose) is givento the freeboard, the package enters into the deaeration module. Theblocks or guiding structures in the deaeration section have a specialinternal curvature. The belts are assembled in a manner such that thereis a greater length on the side on which the belts face each other tofollow the curvature. Moreover, the source of vacuum produced by thehigh flow ventilator which removes the air from behind the beltsconstrains the belts to follow the curvature of the block or guidingstructure. Finally, as the belts are perforated, a certain quantity ofair passes through them so that the upper sides of the package areconstrained to follow the belt and curvature of the block or guidingstructure.

In FIG. 9, the package can be seen along three different stations alongthe system. The steps presented below are shown on the figure.

-   -   A. Module receives packages from packaging machine.    -   B. Bottom of the package is raised prior to vacuum extraction.    -   C. Top of package is forced to open and air is extracted from        package.    -   D. Package exits towards the sealer.

In FIG. 10, the air removal section of the system is seen from above.The two blocks or guiding structures facing each other can be seen, aswell as the package along three different positions during itsdisplacement through the system. The package is represented through boldlines and the hash marks represent the opening through which air isremoved from the inside of the package.

FIGS. 11 to 14 illustrate various aspects of the system duringoperation.

FIGS. 11 a and 11 b show lower and upper positions of the package alongthe conveyor illustrating how tension is removed from the top of thepackage once it is lifted.

FIGS. 12 a to 12 c are side views of the package as it travels along theconveyor system. In this example, the slope is 3 inches over 2 feet,preferably at 150 fpm.

FIGS. 13 a and 13 b illustrate the package before and after removal ofair.

FIGS. 14 a to 14 d are perspective views of the interaction of a packagewith the system shown in FIG. 11, illustrating air extraction, vacuumshutdown and maintenance of the condition of the package afterextraction of air.

Preferably, the present invention offers the following performanceparameters:

-   -   Linear speeds up to 150 fpm    -   Adjustable to bag sizes (conveyor height)    -   No additional freeboard required (to hold the package while        filling it)    -   Maximum footprint length of 7 feet    -   Air removal time estimated at 0.4 second    -   No air entrance into the package (after air extraction and prior        to sealing)

According to the present invention, there is also provided a methodremoving air from an interior of a flexible package before closurethereof, comprising the following steps:

-   -   a) displacing the package along a horizontal direction;    -   b) maintaining continuously an upper part of the package closed        along a significant length of its displacement;    -   c) partially opening the upper part of the package at a specific        location along the length of the system; and    -   d) removing air from the interior of the package when the        package is positioned, at said specific location.

Preferably, the method further comprises the step of decreasing, alongthe length of the displacement, a distance between a means fordisplacing the package in step a) placed under the package and a meansfor maintaining the package closed in step b) to remove vertical tensionfrom the upper part of the package.

A package, after going through the above-described deaeration system ormethod, can then be sealed or closed using any sealing or closing systemknown in the art.

Differences with Respect to the Prior Art

As described in U.S. Pat. No. 7,316,102, packages must go through thehood (see 1^(st) paragraph of the summary of the invention . . . “vacuumextraction hood through which the packages are conveyed”), whereas, inthe present invention, the hood is replaced by a deaeration port and thepackage passes under the port.

As described in U.S. Pat. No. 7,316,102, the open package goes throughthe hood and it is gradually closed by the belts facing each other andlocated in the upper part. In the present invention, the package isclosed when it arrives at the air removal section (the package is heldby the upper driving system belts) and it is partially opened. In fact,a portion of it stays closed while it is still held by the belts. Thispartial opening is done while the package is moving forward.

With the system presented in U.S. Pat. 7,316,102, the upper part of thebag is not held before and during air extraction. On the contrary, inthe present invention; the upper part of the package is continuouslyheld, even during air extraction, ensuring an exact positioning of theupper part of the bag, thus ensuring a constant transfer to the closingsystem and an increase in the closing system reliability and quality ofthe finished product.

In the invention described in U.S. Pat. No. 7,316,102, the upper part ofthe package is not held before the end of air extraction; whereas in thepresent invention, the upper part of the bag is continuously held. Thedistance between the conveyor which supports the lower part of thepackage and the belts supporting the upper parts of the package isadjustable. Consequently, it is possible to control tensions exerted tothe sides of the package when the air is extracted from it. Since thedistance between the conveyor supporting the lower part of the packageand the belts holding the upper part of the package is controlled, thecondition (behaviour) of the flap is also controlled and the distancebetween the closing system and the product level into the bag isdecreased which reduces the freeboard required.

In U.S. Pat. No. 7,316,102, air extraction is made through a big hoodmaintained at a negative pressure. Air is drawn up everywhere aroundseveral packages at the same time. Loss of efficiency is obvious andshould be certainly quantifiable. In the present invention, airextraction is made through an aspiration port. The dimension of the airaspiration end is smaller than the upper part of the packages from whichair is extracted. This small end, located very near the upper part ofthe package offers more efficiency (and increased performance).

Moreover, the system described in U.S. Pat. No. 7,316,102 has avoluminous hood that makes the system more burdensome, even cumbersomeor bulky. The present invention has a small deaeration port allowing arealization of the same functions more efficiently while keeping thesystem dimension to its minimum.

Although the present invention has been explained hereinabove by way ofpreferred embodiments thereof, it should be pointed out that anymodifications to these preferred embodiments within the scope of theappended claims are not deemed to alter or change the nature and scopeof the present invention.

1-9. (canceled)
 10. A system for removal of air from an interior of aflexible package before sealing thereof, the system comprising: a lowerconveyor sub-system for continuously displacing the package along alength of the system; an upper driving sub-system holding continuouslyan upper part of the package, keeping the upper part closed along alength of its displacement, said upper driving sub-system comprising atleast one perforated belt bag-opening sub-system comprising: at leastone pair of adjacent guiding structures, each guiding structure having aprofile surface facing a corresponding profile surface of the oppositeguiding structure; a plurality of driving belts, each belt circulatingaround a corresponding guiding structure of the at least one pair ofguiding structures, each of said belts following a path along thecorresponding profile of the guiding structure on which the driving beltis travelling; a pulley system for driving displacement of the pluralityof driving belts around the guiding structures; and a belt sub-systemvacuum source applying vacuum behind the belts, said at least onebag-opening sub-system spreading partially open the upper part of thepackage at a specific location along the length of the system whenpassing between the profile surfaces of adjacent guiding structures,said upper driving sub-system being synchronized with the lower conveyorsub-system; and a deaeration port located above the bag-openingsub-system allowing removal of air from the interior of the package whenthe package is positioned under the port.
 11. The system according toclaim 10, wherein a distance between a top surface of the lower conveyorsub-system and the upper driving sub-system decreases along the lengthof the system to remove vertical tension from the upper part of thepackage.
 12. The system according to claim 10, wherein the bag-openingsub-system repositions the package and allows passage of a certainquantity of air.
 13. The system according to claim 10, wherein each ofthe guiding structures is a block comprising a concave surface.
 14. Amethod for removing air from an interior of a flexible package beforesealing thereof, comprising the following steps: a) providing a systemfor removal of air comprising: a lower conveyor sub-system forcontinuously displacing the package along a length of the system; anupper driving sub-system holding continuously an upper part of thepackage, keeping the upper part closed along a length of itsdisplacement, said upper driving sub-system comprising at least oneperforated belt bag-opening sub-system comprising: at least one pair ofadjacent guiding structures, each guiding structure having a profilesurface facing a corresponding profile surface of the opposite guidingstructure; a plurality of driving belts, each belt circulating around acorresponding guiding structure of the at least one pair of guidingstructures, each of said belts following a path along the correspondingprofile of the guiding structure on which the driving belt istravelling; a pulley system for driving displacement of the plurality ofdriving belts around the guiding structures; a belt sub-system vacuumsource applying vacuum behind the belts, said at least one bag-openingsub-system spreading partially open the upper part of the package at aspecific location along the length of the system when passing betweenthe profile surfaces of adjacent guiding structures, said upper drivingsub-system being synchronized with the lower conveyor sub-system; and adeaeration port located above the bag-opening sub-system allowingremoval of air from the interior of the package when the package ispositioned under the port, b) displacing continuously the package alonga horizontal direction, using the low conveyor sub-system; b)maintaining continuously an upper part of the package closed along alength of its displacement, using the upper driving sub-system; c)partially opening the upper part of the package at a specific locationalong the length of the system, using said bag-opening sub-system; andd) removing air from the interior of the package when the package ispositioned, at said specific location, using the deaeration port. 15.The method according to claim 14, further comprising the step ofdecreasing, along the length of the displacement, a distance between thelower conveyor sub-system and the upper driving sub-system to removevertical tension from the upper part of the package.
 16. The methodaccording to claim 15, wherein each of the guiding structures is a blockcomprising a concave surface.
 17. A system for removing air from aninterior of a flexible package before sealing thereof, comprising:displacement means for continuously displacing the package along ahorizontal direction while supporting a bottom of the package andholding an upper part of the package at all times; raising means forraising the bottom of the package along a distance of travel of thepackage to reduce vertical tension within the package; and opening meansfor opening a portion of the upper part of the package, said openingmeans comprising: at least one pair of guiding structures, each guidingstructure having a profile surface facing a corresponding profilesurface of the opposite guiding structure; a plurality of driving belts,each belt circulating around a corresponding guiding structure of the atleast one pair of guiding structures, each of said belts following apath along the corresponding profile of the guiding structure on whichthe driving belt is travelling; a pulley system for driving displacementof the plurality of driving belts around the guiding structures; and abelt sub-system vacuum source applying vacuum behind the belts, saidbag-opening sub-system spreading partially open the upper part of thepackage at a specific location along the length of the system whenpassing between the profile surfaces of adjacent guiding structures,while maintaining displacement of the package; and a deaeration portlocated above the opening means allowing removal of air from theinterior of the package when the package is positioned under the port.